The two arrows on the right side of the cca allow you to play with different dates. Reading Ludwig Oechslin’s hundred year calendar becomes intuitive after a very short time on the wrist.
1. Reading the date The 30 + 1 rectangles around the perimeter of the dial display the date. The white 10 minute marker serves as reference points. For example the yellow rectangle points to 4 o’clock white marker it is the 10st day of the month (20 ÷ 2 = 10). Other example, yellow rectangle points 6 o’clock it is the 15st day (30 ÷ 2 = 15).
2. Reading the months The white point on the center disk indicates the month and also the leap year. When the white dot is at 1 o’clock, it’s January. When the white dot marks 6 o’clock, it’s July. And when the white dot marks 12 o’clock, it is December. The month disk rotates clockwise.
3. Reading the Leap and common years The month disk includes a smaller disk with a white marker showing the leap year if pointing to the white dot. The marker rotates clockwise at 90° showing the three common years. The leap year disc rotates clockwise with the month disc.